EMPIRICAL MODELING OF THIN LAYER DRYING CHARACTERISTICS OF NAUCLEA LATIFOLIA LEAVES
The thin layer drying characteristics of Nauclea latifolia leaves were studied at four drying
temperatures of 35, 45, 55 and 65oC and a constant air velocity of 1.5 m/s in a convective dryer.
Experimental kinetic data were fitted to four established drying models available in the literature,
namely: the Newton, Henderson and Pabis, Page and Logarithmic models. Model parameters were
determined by using non-linear regression analysis while the goodness of fit was assessed by the
coefficient of determination (R2), root mean square error (RMSE) and the standard error (SE). Fick’s
diffusion model and Arrhenius-type equation were used to determine the effective diffusivity and
activation energy, respectively. The increase in air temperature significantly reduced the drying time of
the Nauclea latifolia leaves. Among the models proposed, the Page model was found satisfactory for
describing the air-drying kinetics of Nauclea latifolia leaves. The effective diffusivity increases as
temperature increases and ranged between 3.3841 E-08 - 1.1202 E-07 m2/s while the activation energy
of diffusion was estimated to be 40.55 kJ/mol.